How to be a Skeptic: A Defense of Certainty-Based Invariantism

Abstract

Do I know that my bank is open on Saturday? If nothing much rides on the answer, I will happily say yes. But if my rent is due Monday, or someone reminds me that banks change their hours without notice, I suddenly feel less willing to say that I know. This is most puzzling. It seems that whether we count as knowing something can depend not on the evidence, but on how much is at stake or on being reminded that we might be wrong. Many philosophers explain this by claiming that the very meaning of "knowledge" shifts from context to context. I argue for something different. I defend the view that we ascribe knowledge only once we feel certain enough about something to stop questioning it, and that this feeling of certainty is precisely what stakes and reminders of error can unsettle. Combining philosophical argument with original experiments, I build this into a full theory of knowledge utterances, one that also explains why skepticism, the view that we know far less than we think, feels so alien. My conclusion: skepticism’s strangeness flows out of the impracticality of getting rid of the feeling of certainty with which we accompany most of our mundane beliefs. To be a skeptic, then, is not to walk that treacherous road: it is enough to own our cognitive limitations, while we keep talking about knowledge as we always have.